EP2719615B1 - Fixing device - Google Patents

Description

The invention relates to a device for fastening a multi-sprocket on a hub of a rear wheel of a bicycle. In this case, the multi-sprocket differently sized sprockets for receiving a chain and for transmitting a force introduced by the chain circumferential force on the hub, with the ability to switch the chain by a switching device from one to another sprocket.

In multi-sprockets of the conventional type, a cassette consisting of a plurality of sprockets of different diameters is placed on a driver of a hub. The teeth of each sprocket come alternately in engagement with the chain when operating the switching device and transmit torque from the pedal forces of the driver on the impeller via a profile that rotatably connects the sprockets with the impeller. Each of these sprockets thus transmits individually the torque to the driver, which means that it must be made stronger and heavier both in the field of entrainment on the profile of the driver, as well as on the sprocket because of seitseitlich acting forces through the usually out of alignment chain.

To meet different requirements, for example in the cycling, for ever lighter construction, or due to increased accuracy requirement in conjunction with a further increase in the number of gear ratios, the approach has been implemented to a one-piece design of multiple-pinion assemblies.

So is out of the EP 1 972 539 a multiple pinion arrangement has become known, in which the individual pinions are arranged in a conical support structure in which alternate tubular sections and disc-shaped sections in steps and in which the individual pinions are formed by a disc-shaped portion and arranged at the periphery of teeth for engagement with the roller chain , The support structure can be formed with very small wall thickness, which is limited primarily by the manufacturing tolerances down.

In the EP 1 342 657 A2 disclosing the preamble of claim 1, there is shown a multiple pinion arrangement showing a rotation limiting device of rotation limiters on the pinions.

In multi-pinion arrangements, which consist of individual pinions, the individual pinions are also each rotatably connected to the driver. Serve torque-transmitting gears that produce a positive connection between the pinion and the impeller. In addition, several adjacent single pinion can be connected by screws together to form a sprocket set, spacer rings ensure compliance with a defined distance in the axial direction between the individual pinions. This makes it easier to postpone a sprocket set on the toothing, which is necessary in the case of wear of the teeth on the pinions and the need for replacement with new sprockets. Here is the smallest single pinion a special task in terms of secure fixation on the impeller.

For the axial fixation of the sprocket set a fastening screw is used in each case, which is screwed with its external thread into an internal thread on the impeller. Tool surfaces on the fastening screw serve to engage a tool in order to be able to apply torque to the fastening screw both for tightening and loosening the fastening screw.

In the drive case, the impeller and the sprocket set rotate under the attacking at the same outlet angle on the pinion chain chain, and it constantly changes the force application point of the chain tension on the sprocket set on the combination of impeller and pinion.

the driver is possible. As the sprocket pack rotates relative to the impeller, the sprocket set therefore rolls on the outer peripheral surface of the sprocket, tending to rotate at a smaller angle than the sprocket. Due to the rotational disability between the sprocket set and impeller by engaging projections on the sprocket set, there is a reciprocating Walk movement of the sprocket set relative to the impeller. This flexing movement can contribute to the loosening of the fastening screw, which causes the fastening screw to turn loose and no longer maintain a desired connection between the pinion pack and the driver. As a countermeasure knurling elements have proven both on the fastening screw, and the smallest pinion, which are arranged with a radial extent with respect to the axis of rotation of the pinion and on the other hand engage due to the axial bias between a contact with the driver on the one hand and the head of the fastening screw , If it now comes to a Walk movement of the smallest pinion against the impeller in the limits that are predetermined by the teeth, the fixing screw can not be solved. Rather, it moves together with the reciprocating movement of the smallest pinion in the aforementioned Walk movement, because the knurling prevents further movement between the smallest pinion and mounting screw.

The individual knurling elements are aligned radially, according to the obstructing rotational movement between the smallest pinion and fastening screw. In a smallest pinion produced by stamping and forming the mold elements are impressed, including complementary mold elements are present on the corresponding embossing tools. The production of the mold elements takes place in a way, incidentally, without the implementation of additional, the production costs negatively affecting processing steps.

The situation is different with sprocket sets that are produced by machining processes. Then, by turning operations and subsequent milling operations forming work steps are carried out in which not incidentally even the form elements of the knurling can arise. Rather, additional, additional processing steps would have to take place, with additional processing times and processing costs. Particularly disadvantageous here from the fact that the form elements of the knurling just because of their radial orientation just not a milling operation, and certainly not the possibilities of turning counter.

It is therefore the task of a sprocket set, which is produced by machining manufacturing process, to provide a cost-effective way of providing a rotationally fixed connection between the fastening screw and the sprocket set. This problem is solved by splitting the sprocket set into at least two components, namely a separate ring element in addition to the already existing sprocket set. These two components are rotatably coupled to each other by means of rotary coupling elements, wherein on one of the components a knurling is formed, which does not have to be incorporated in the context of machining the sprocket with, but with the help of cheaper methods, such as with an embossing process.

Although the production of the mentioned Rädelelemente, which act as a rotary coupling elements, although also requires additional manufacturing costs. However, it has been found that these costs are lower compared to the manufacture of the knurling with machining production processes, which are optimized with regard to the processing of the sprocket set, lower. It is therefore also not excluded to perform the knurling even on a spun with respect to the sprocket package component with an optimized for this component cutting operation, because it first and foremost on the splitting into several components arrives, each of which can be optimized by itself.

A corrugation on a ring element for a sprocket for a bicycle is in the FR 1 195 874 shown.

Washers with different directional orientation at a nip for a cable to a bicycle are in the EP 0 766 014 disclosed.

• Fig. 1 zeigt ein einstückiges Ritzelpaket, das mittels spanender Herstellungsverfahren entstanden ist und für die Anwendung der erfindungsgemäßen Lösung vorgesehen ist.
• Fig. 2 zeigt die erfindungsgemäße Ausbildung einer Ritzelanordnung in Verbindung mit einem Ringelement mit Rändelelementen.
• Fig. 3 zeigt eine bevorzugte Ausführungsform eines erfindungsgemäßen Ringelementes mit Rändeln.
• Fig. 4 zeigt Details einer bevorzugten Ausführungsform eines erfindungsgemäßen Ringelementes mit Rändeln.

The solution according to the invention is described below using the example of a preferred embodiment.

• Fig. 1 shows a one-piece sprocket package, which has arisen by means of machining production method and is provided for the application of the inventive solution.
• Fig. 2 shows the inventive construction of a pinion assembly in conjunction with a ring element with knurled elements.
• Fig. 3 shows a preferred embodiment of a ring element according to the invention with knurling.
• Fig. 4 shows details of a preferred embodiment of a ring element according to the invention with knurling.

In Fig. 1 an arrangement of a one-piece sprocket set 1, a final disc 13, a spacer sleeve 14 and a separate smallest pinion 17 is shown, which is arranged on an unillustrated driver of a bicycle rear hub rotatable relative to the hub axle, also not shown. For the purpose of rotational coupling engage both engagement projections 15 on the end plate 13, and first rotation limiter 7 on the smallest pinion 17 in provided on the impeller depressions. Also for rotational coupling engaging pins 16 on the sprocket set 1 in corresponding holes on the end plate 13 a. By a fixing screw, not shown, to arrange in the figure right from the smallest pinion 17, the smallest pinion 17, the sprocket set 1, the spacer sleeve 14 and the end plate 13 are biased against an axial collar of the drive. In this case, a step-shaped support structure of the sprocket set 1 is axially slightly compressed until the spacer sleeve 14 comes after use of an axial clearance with the smallest pinion 17 and the end plate 13 into abutment. The smallest pinion 17 represents a ring element 2 with radially outwardly projecting pinion teeth 11 and has first knurling elements 5.

In the process of moving the drive chain from the smallest sprocket 17 to the adjacent larger single sprocket on the sprocket set 1 for the purpose of gear shifting, a defined association between the respective pinion teeth 11 with respect to their relative angular position about the axis of rotation of the drive is of crucial importance to the transfer operation. In this relative angular position go, as both the pinion package 1, and the smallest pinion 17 are oriented angularly to the driver. The advantage of a precise angular assignment, as it exists between the individual pinions on the sprocket set 1, does not exist here.

Also, the diameter of the smallest pinion 17 and thus the number of teeth is limited by the outer diameter of the driver down.

The Fig. 2 shows an arrangement of a sprocket set 1, a ring member 2 and a threaded member 3 for mounting on the impeller on a bicycle rear hub. The sprocket set 1 is produced in one piece by means of cutting processes, such as turning and milling, and also contains the smallest sprocket 17. The integration of the smallest sprocket 17 is therefore particularly advantageous because it enables very small numbers of teeth to be realized. Otherwise, a small separate pinion, especially for very small numbers of teeth a very graceful construction, because on the inner circumference driving elements to the driver or other kind of coupling elements must be provided, which must correspond to the diameter of the driver. The number of teeth 11 therefore represents a limit of feasibility with common diameter ratios.

By a threaded member 3 with second knurled elements 6, the pinion package 1 with the smallest pinion 17 and a ring member 2 are exposed to an axial force and braced against each other. The first knurling elements 5 on the ring element 2 engage in the interspaces between the second knurling elements 6 on the threaded element 3 in order to prevent loosening of the threaded element 3. In the embodiment shown in the axial space between the first knurled elements 5 and second knurling elements 6 is still a spring washer 12 is arranged, which is bent according to the knurling in the axial direction and the locking effect of the knurled elements 5, 6 decreases. The spring washer 12 can due to the flexibility present in the axial direction of the Sprocket sets 1 also omitted. The engagement of a tool are tool surfaces 18 on the inner periphery of the threaded element. 3

The threaded element 3 is screwed with its external thread in the internal thread on the impeller. With appropriate diameter ratios, an internal thread could be provided on the threaded element 3, for screwing on an external thread on the driver.

The FIG. 3 shows the complete ring element 2, and the FIG. 4 Details of it. From a disc-shaped base body 9 are first rotation limiter 7 in the axial direction. They are in the mounted state with second rotation limiters 8 on the sprocket set 1 in engagement and prevent twisting of the ring element 2 relative to the sprocket set 1, which is necessary when tightening the mounting screw 3. The Drehbegrenzer 8 as recesses in the sprocket set 1 are easy to bring in the production of the sprocket set 1 with. As an alternative, the above form elements would also be conceivable.

The large number of filigree, but necessarily exactly to be manufactured first knurling elements 5 on the ring element 2 makes it clear that a production with machining production process means a lot of effort. This problem is inventively solved with the provision of a separate, non-rotatable relative to the sprocket set 1 ring element 2, for the other, cheaper manufacturing process in question, such as by punching and embossing. It has been shown that the additional expense associated with arranging the first and second rotation limiters 6, 7 is comparatively lower.

reference numeral

1

sprockets

2

ring element

3

threaded element

4

Rändelverzahnung

5

first knurling element

6

second knurling element

7

first turn limiter

8th

second turn limiter

9

disc-shaped body

10

Rotation limiting device

11

pinion

12

spring washer

13

Final disc

14

Stand Off

15

engaging projection

16

engagement pin

17

smallest pinion

18

tool surfaces

Claims (3)

1. Fastening device for fastening a sprocket assembly (1) on the driver on a bicycle rear wheel hub of a bicycle;
   with the sprocket assembly (1), a ring element (2) and a threaded element (3), and with first knurled elements (5) on the ring element (2) and second knurled elements (6) on the threaded element (3), the knurled elements (5, 6) together forming a knurled toothing system (4); the sprocket assembly (1) and the ring element (2) being braced against one another in the axial direction by way of the threaded element (3);
   a rotation limiting apparatus (10) being provided between the ring element (2) and the sprocket assembly (1), which rotation limiting apparatus (10) consists of a first rotation limiter (7) on the ring element (2) and of a second rotation limiter (8) on the sprocket assembly (1), which rotation limiters engage into one another and limit the rotation capability between the ring element (2) and the sprocket assembly (1); characterized in that, furthermore, a smallest sprocket (17) is connected in one piece to the sprocket assembly (1).
2. Fastening device according to Claim 1, characterized in that the ring element (2) has a disc-shaped main body (9), and in that the first rotation limiter (7) projects axially with respect to the disc-shaped main body (9).
3. Fastening device according to Claim 1, characterized in that the sprocket assembly (1) has a closure disc (13).

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